FESADev/docs/releases/linear-static-3d-euler-beam-release.md

# Linear Static 3D Euler Beam Release Report

## Metadata

- feature_id: `linear-static-3d-euler-beam`
- approved_design: `docs/superpowers/specs/2026-08-08-linear-static-3d-euler-beam-design.md` (`status: approved`; approved 2026-08-08, amended 2026-08-09)
- source_requirement: `docs/requirements/linear-static-3d-euler-beam.md`
- source_research: `docs/research/linear-static-3d-euler-beam-research.md`
- source_formulation: `docs/formulations/3d-isoparametric-euler-beam-formulation.md`
- source_numerical_review: `docs/numerical-reviews/linear-static-3d-euler-beam-review.md`
- source_io_definition: `docs/io-definitions/linear-static-3d-euler-beam-io.md`
- source_reference_model: `docs/reference-models/linear-static-3d-euler-beam-reference-models.md`
- source_implementation_plan: `docs/implementation-plans/linear-static-3d-euler-beam.md`
- source_implementation_report: `docs/implementation-plans/linear-static-3d-euler-beam-implementation-report.md`
- source_build_test_report: `docs/build-test-reports/linear-static-3d-euler-beam.md`
- source_reference_verification_report: `docs/reference-verifications/linear-static-3d-euler-beam-reference-verification.md`
- source_physics_evaluation_report: `docs/physics-evaluations/linear-static-3d-euler-beam-physics-evaluation.md`
- audited_head: `822b06be3d2128d5dfdc5e394078abbb9dcd5a50`
- reference_model_id: `cantilever-beam-b33`
- reference_schema: `abaqus-cae-report-csv-v0`
- reference_baseline: `reference/cantilever beam/` at source commit `2b34d0b`
- status: `ready-for-release`
- owner_agent: `release-agent`
- date: `2026-08-10`

This is an internal feature-readiness verdict. It authorizes no publish, deploy, package, tag,
push, external release, or reference-artifact operation.

## Release Scope

| item | included | excluded | notes |
| --- | --- | --- | --- |
| analysis | one small-displacement/small-rotation `*STEP, *STATIC` linear solve | multiple steps; geometric/material nonlinearity; dynamics; contact; thermal | Stiffness/partition and `Kff` factorization precede load assembly, effective RHS, and substitution. |
| element | straight, prismatic, two-node 3D Euler-Bernoulli beam mapped only from `TYPE=B33` | `TYPE=B31`, shear-deformable/Timoshenko, curved/tapered/released/offset/warping members | Axial, two-plane bending, and Saint-Venant torsion are included. |
| material/section | homogeneous isotropic linear elasticity; positive `E,G,A,Iy,Iz,J`; `I12=0` | `I12!=0`, anisotropy, plasticity, temperature dependence, warping data | Mapping is `n1 -> local y`, `t x n1 -> local z`, `Iy=I11`, `Iz=I22`. |
| Abaqus input subset | approved keyword inventory, identity part/assembly/instance wrappers, `*BOUNDARY`, nodal `*CLOAD` | full compatibility, instance transforms, nested assembly, dependent/independent mesh semantics, `*DLOAD` | Approved output-request allowlist is warning no-op and cannot filter FESA output. |
| solver/storage | deterministic COO-to-0-based-CSR, oneTBB element-local work, oneMKL PARDISO SPD factorization/substitution | alternate solver claims, automatic regularization, unsupported conditioning policy | Backend types remain behind adapters. |
| authoritative output | HDF5 `results.h5`: displacement, reaction, equilibrium end action, section/generalized results, axial `S11`, metadata, diagnostics | official FESA CSV output; transverse/torsional shear stress; warping stress; nodal stress averaging | Beam stress reference comparison is N/A; `S11` remains mandatory and is analytically/schema tested. |
| reference comparison | exact read-only legacy B33 four-file bundle; displacement, reaction, section resultant | Abaqus stress CSV; broad B33 compatibility; reference solver execution | 176/176 rows and 16/16 metrics passed the approved mixed tolerance. |

## Gate Evidence Inventory

| gate | source | expected status | observed status/evidence | verdict |
| --- | --- | --- | --- | --- |
| approved design | approved design | `approved` | `approved`; same feature and legacy baseline | pass |
| requirements | requirements baseline | `approved` | `approved`; 44 consecutive `must` rows | pass |
| research | research brief | `ready-for-formulation` | `ready-for-formulation`; applicability limits retained | pass |
| formulation | formulation document | `ready-for-numerical-review` | `ready-for-numerical-review`; exact requirement/design links | pass |
| numerical review | numerical review | `pass-for-implementation-planning` | `pass-for-implementation-planning`; no confirmed mathematical defect | pass |
| I/O definition | I/O contract | `ready-for-implementation-planning` | `ready-for-implementation-planning` | pass |
| reference model | reference-model contract | `ready-for-implementation-planning` | legacy inventory/provenance and analytical portfolio defined | pass |
| implementation plan | implementation plan | `ready-for-implementation` | `ready-for-implementation`; TASK-07 through TASK-24 defined | pass |
| implementation evidence | implementation report plus phase index | all Step 7-24 blocks completed | 18/18 Step blocks and index entries `completed`; final cumulative suite 83 tests | pass with stale-header note below |
| build/test | build/test report | `pass-for-reference-verification` | `pass-for-reference-verification`; fresh MSVC x64 Debug build, warning count 0, 83/83 | pass |
| reference verification | reference-verification report | `pass-for-physics-evaluation` | `pass-for-physics-evaluation`; 176/176 rows and 16/16 metrics | pass |
| physics evaluation | physics-evaluation report | `pass-for-release-agent` | `pass-for-release-agent`; all documented physics checks and 17/17 targeted tests pass | pass |
| phase sequence | phase index | Steps 0-27 `completed` | 28/28 prerequisite entries completed in gate order | pass |

### Identity and contradiction audit

- All feature-level reports use `linear-static-3d-euler-beam`, the same approved design path,
  authoritative HDF5 contract, logical model `cantilever-beam-b33`, legacy schema, and exact
  `reference/cantilever beam/` baseline from `2b34d0b`.
- The formulation metadata uses the narrower element-document identity
  `3d-isoparametric-euler-beam`. This is not a competing release feature: it names the exact
  formulation path referenced by the approved feature requirements, design, numerical review,
  I/O contract, reference-model contract, and implementation plan. Its `source_requirement` and
  `approved_design` links establish the same release lineage.
- The implementation report aggregate metadata still says `status: in-progress`. This is a stale
  aggregate header, not an unresolved release gate: every TASK-07 through TASK-24 block is
  `completed`, all corresponding phase-index entries are `completed`, Step 25 independently audited
  all 18 blocks, and a fresh build/discovery/full CTest passed 83/83. The Step 25 report reaches the
  same explicit nonblocking conclusion. The upstream implementation report was not modified.
- The Step 26 report records two nonblocking evidence-text defects: its sample acceptance probe
  expects a nonexistent string `status` although the authoritative JSON/code/tests use
  `passed=true`, and the Step 25 prose contains a typo in the input SHA-256. Fresh Step 26/27 hashes,
  Git diff/status, exact row reconstruction, and passing comparison evidence preserve artifact
  identity; neither defect changes code, tolerance, or the verdict.

## Acceptance Traceability

Evidence aliases used below are exact upstream identities: `BT25` is the build/test report;
`RV26` is the reference-verification report; `PE27` is the physics-evaluation report. Model IDs
(`an-*`, `cv-*`, `neg-b33-input-contract`, `cantilever-beam-b33`) and `NR-T01` through `NR-T11`
are defined by the approved reference-model and numerical-review documents. Every row has priority
`must` in the approved Requirement Verification Matrix.

| requirement | acceptance criterion | exact test/evidence IDs | reference or analytical evidence | final disposition |
| --- | --- | --- | --- | --- |
| `FESA-REQ-LS3DEB-001` | One static step runs; a second step is rejected structurally. | `T12-MAP-001`, `T12-MAP-004`, `T13-MODEL-003`, `T24-CLI-001` | `smoke-b33-cli`; `neg-b33-input-contract`; `BT25` | released-in-V0 |
| `FESA-REQ-LS3DEB-002` | Accepted models obey the straight/prismatic/two-node, small linear-static scope and exclusions are not claimed. | `T12-MAP-001`, `T12-MAP-004`, `T16-BEAM-006`, `T24-ORCH-002` | `CB-AXIAL-TIP`, `CB-TORSION-TIP`, both bending candidates; `PE27` model coverage | released-in-V0 |
| `FESA-REQ-LS3DEB-003` | DOF and nodal-result order is exactly `[UX,UY,UZ,URX,URY,URZ]`. | `T14-DOF-001`, `T15-STATE-002`, `T23-HDF5-001` | `cantilever-beam-b33`; `RV26` HDF5 audit | released-in-V0 |
| `FESA-REQ-LS3DEB-004` | Axial, torsion, local-y bending, and local-z bending recover approved analytical quantities. | `T16-BEAM-006`, `T22-RECOVERY-004`, `NR-T08-ANALYTICAL` | `an-b33-axial-cantilever`, `an-b33-torsion-cantilever`, `an-b33-local-y-bending`, `an-b33-local-z-bending`; `PE27` | released-in-V0 |
| `FESA-REQ-LS3DEB-005` | Only B33 creates the approved Euler beam semantic object. | `T12-MAP-001`, `T24-B33-001` | `cantilever-beam-b33`; `RV26` confirms `TYPE=B33` | released-in-V0 |
| `FESA-REQ-LS3DEB-006` | B31 returns exact `unsupported-element-formulation` and creates no Euler beam. | `T12-MAP-004` | `CB-B31-NEGATIVE`; `neg-b33-input-contract` | released rejection behavior; B31 unsupported |
| `FESA-REQ-LS3DEB-007` | DOFs 1..6 map correctly and nonzero `dc` affects RHS and reaction. | `T14-DOF-002`, `T19-CONSTRAINT-003`, `T21-LOAD-001`, `T21-LOAD-003`, `T22-RECOVERY-001` | `an-b33-prescribed-displacement`; `NR-T09-PARTITION-SPD`; `PE27` | released-in-V0 |
| `FESA-REQ-LS3DEB-008` | Closed-form line-load vector passes while parser/CLI `*DLOAD` and Domain distributed load remain absent. | `T16-BEAM-005`, `T12-MAP-005`, `NR-T06-LINE-LOAD` | `an-b33-line-load-kernel`; `PE27` targeted portfolio | released kernel; `*DLOAD` unsupported |
| `FESA-REQ-LS3DEB-009` | Every approved keyword has positive coverage and no unlisted support claim exists. | `T12-MAP-001`, `T12-MAP-004` | `smoke-b33-cli`; exact I/O keyword inventory; legacy input | released approved subset only |
| `FESA-REQ-LS3DEB-010` | Case variants/comments behave correctly and raw source identity survives. | `T11-SYN-001`, `T11-SYN-002`, `T10-DOM-001` | legacy input exact-byte identity `fnv1a64:04543464cc970405`; `RV26` | released-in-V0 |
| `FESA-REQ-LS3DEB-011` | Only approved boundary/load arities and DOFs pass; target expansion is deterministic. | `T12-MAP-001`, `T12-MAP-002`, `T12-MAP-004`, `T14-DOF-002`, `T21-LOAD-001` | analytical load/BC fixtures; invalid-target portfolio | released-in-V0 |
| `FESA-REQ-LS3DEB-012` | Section properties and right-handed local-axis mapping match the contract. | `T12-MAP-001`, `T12-MAP-004`, `T16-BEAM-004`, `NR-T05-TRANSFORM` | both bending models; `an-b33-rotated-space`; `PE27` local/global signs | released-in-V0 |
| `FESA-REQ-LS3DEB-013` | Valid `E,nu`/derived `G` and positive section properties pass; malformed/nonpositive data fails. | `T12-MAP-001`, `T12-MAP-004`, `T16-BEAM-007` | analytical inventory; `neg-b33-input-contract` invalid properties | released-in-V0 |
| `FESA-REQ-LS3DEB-014` | Exact scale-aware length/guide thresholds reject boundary failures and valid geometry gives an orthonormal frame. | `T12-MAP-004`, `T16-BEAM-004`, `T16-BEAM-007`, `NR-T05-TRANSFORM` | `neg-b33-input-contract`; rotated-space analytical model | released-in-V0 |
| `FESA-REQ-LS3DEB-015` | Instance/source labels round-trip to stable unique internal IDs. | `T10-DOM-001`, `T10-DOM-002`, `T12-MAP-002`, `T23-HDF5-001` | multi-instance semantic fixture; `RV26` model identity audit | released-in-V0 |
| `FESA-REQ-LS3DEB-016` | Multiple identity instances remain distinct and deterministic. | `T10-DOM-003`, `T12-MAP-002` | multi-instance semantic fixture; reference CSV N/A | released-in-V0 |
| `FESA-REQ-LS3DEB-017` | Instance translation/rotation fails with exact `unsupported-instance-transform`. | `T12-MAP-004` | `neg-b33-input-contract` transform case | released rejection behavior; transforms unsupported |
| `FESA-REQ-LS3DEB-018` | Nested/dependent constructs fail structurally and produce no Domain model. | `T12-MAP-004` | `neg-b33-input-contract` nested/dependent cases | released rejection behavior; nested assembly unsupported |
| `FESA-REQ-LS3DEB-019` | Exact no-op allowlist emits deterministic warnings without semantic effect. | `T12-MAP-003`, `T23-HDF5-002`, `T23-HDF5-003` | legacy input/output requests; `RV26` mandatory-output audit | released-in-V0 |
| `FESA-REQ-LS3DEB-020` | Unlisted model keywords fail and allowed output requests cannot suppress mandatory HDF5 output. | `T12-MAP-004`, `T23-HDF5-002`, `T24-CLI-003` | `smoke-b33-cli`; `RV26` exact HDF5 inventory | released-in-V0 |
| `FESA-REQ-LS3DEB-021` | Active-step view neither copies nor mutates Domain. | `T10-DOM-002`, `T13-MODEL-002` | architecture/code-verification fixture; reference CSV N/A | released-in-V0 |
| `FESA-REQ-LS3DEB-022` | DofManager exclusively owns mapping/scatter/reconstruction; Node/Element have no equation IDs. | `T14-DOF-001`, `T14-DOF-003`, `T14-DOF-004`, `T19-CONSTRAINT-001` | code/dependency audit; reference CSV N/A | released-in-V0 |
| `FESA-REQ-LS3DEB-023` | Required V0 state is connected to output and excluded state is unallocated. | `T15-STATE-001`, `T15-STATE-002`, `T23-HDF5-001` | `smoke-b33-cli`; `RV26` HDF5 audit | released-in-V0 |
| `FESA-REQ-LS3DEB-024` | Repeated/thread-varied assembly has identical CSR order and values. | `T17-PFOR-002`, `T18-SPARSE-002`, `T18-SPARSE-004`, `T18-SPARSE-005`, `NR-T11-DETERMINISTIC-ASSEMBLY` | `cv-b33-patch-rigid-assembly`; reference CSV N/A | released-in-V0 |
| `FESA-REQ-LS3DEB-025` | Backend types do not leak and dense/sparse storage matches contract. | `T07-BUILD-002`, `T09-DENSE-001`, `T09-DENSE-002`, `T18-SPARSE-001`, `T20-PARDISO-004`; Step 25 dependency scans | adapter/code audit; `BT25` | released-in-V0 |
| `FESA-REQ-LS3DEB-026` | Event trace is stiffness/partition/factorize/load/RHS/solve with separate factorization. | `T20-PARDISO-002`, `T24-ORCH-001` | lifecycle event-trace fixture; `BT25` | released-in-V0 |
| `FESA-REQ-LS3DEB-027` | Effective RHS, full displacement, and residual reaction satisfy partition equations. | `T19-CONSTRAINT-001`, `T19-CONSTRAINT-003`, `T21-LOAD-003`, `T22-RECOVERY-001`, `T22-RECOVERY-002`, `NR-T09-PARTITION-SPD` | `an-b33-prescribed-displacement`; `PE27` residual/reaction checks | released-in-V0 |
| `FESA-REQ-LS3DEB-028` | Success atomically produces final HDF5 and failure leaves no incomplete final file. | `T23-HDF5-004`, `T23-HDF5-005`, `T24-CLI-001` | CLI writer success/failure fixtures; `RV26` authoritative output | released-in-V0 |
| `FESA-REQ-LS3DEB-029` | Every schema-v0 path exists at frame 0 with exact rank/component identity. | `T23-HDF5-001`, `T24-B33-001` | `RV26` read-only HDF5 schema audit | released-in-V0 |
| `FESA-REQ-LS3DEB-030` | Metadata fields, ordinary unit label, and external SI provenance are exact. | `T07-BUILD-001`, `T23-HDF5-001`, `T24-CLI-001`, `T24-B33-001` | `cantilever-beam-b33`; `RV26` metadata/source-identity audit | released-in-V0 |
| `FESA-REQ-LS3DEB-031` | Component order and endpoint/Gauss locations are exact and output-request independent. | `T15-STATE-002`, `T16-BEAM-006`, `T22-RECOVERY-003`, `T23-HDF5-001`, `T23-HDF5-002`, `T24-CLI-003` | all analytical models; `RV26`; `PE27` end/section checks | released-in-V0 |
| `FESA-REQ-LS3DEB-032` | Correct `S11` rows/default centroid exist, no shear stress is emitted, and stress reference is N/A. | `T16-BEAM-008`, `T22-RECOVERY-005`, `T23-HDF5-003`, `T24-B33-001` | axial/local-z analytical stress; `RV26` Stress Reference Status; `PE27` stress sanity | released; Abaqus stress reference N/A |
| `FESA-REQ-LS3DEB-033` | Default/explicit output and exact exit-code/ordered-diagnostic contract pass. | `T08-CORE-002`, `T24-CLI-001`, `T24-CLI-002` | CLI negative portfolio; `BT25` | released-in-V0 |
| `FESA-REQ-LS3DEB-034` | Every production step has RED, GREEN, focused/full VERIFY, discovery, and no warning. | `T07-*` through `T24-*`; TASK-07 through TASK-24 report blocks | `BT25`: 18/18 blocks audited, fresh warning count 0, 83 discovered, 83/83 pass | satisfied |
| `FESA-REQ-LS3DEB-035` | All matrix, mode, residual, transform, partition, and analytical thresholds pass. | `T16-BEAM-001` through `T16-BEAM-010`; `T18-SPARSE-004`; `T19-CONSTRAINT-003`; `T20-PARDISO-001`, `T20-PARDISO-006`; `T22-RECOVERY-002`; `NR-T01` through `NR-T11` | analytical portfolio; `PE27` exact targeted 17/17 | satisfied |
| `FESA-REQ-LS3DEB-036` | Abaqus-only component scale and exact mixed formula apply to every row. | `T24-REF-002`, `T24-B33-001` | `RV26`: 176 recalculated row decisions, 16 metrics | satisfied |
| `FESA-REQ-LS3DEB-037` | Exact SI floors and zero-scale behavior are applied. | `T24-REF-002`, `T24-B33-001` | `RV26` component table includes zero-scale groups and exact floors | satisfied |
| `FESA-REQ-LS3DEB-038` | Invalid row/schema/identity/nonfinite cases fail before tolerance; no clamp/drop occurs. | `T24-REF-001`, `T24-REF-002` | malformed contract fixtures; `RV26` zero missing/extra/duplicate/nonfinite rows | satisfied |
| `FESA-REQ-LS3DEB-039` | Every row decision and aggregate/worst metric is present. | `T24-REF-003`, `T24-B33-001` | `RV26`: 176 ledger rows, 16 component metrics, exact recomputation | satisfied |
| `FESA-REQ-LS3DEB-040` | Exact legacy filenames exist and reference content is unchanged. | `T11-SYN-004`, `T24-B33-001`; `BT25`/`RV26`/`PE27` reference diff/status checks | exact approved four-file bundle and pre/post hashes | satisfied legacy exception |
| `FESA-REQ-LS3DEB-041` | Four-file/B33/header/key/finite precheck passes before comparison with approved failure classes. | `T24-REF-001`, `T24-B33-001` | `RV26` Artifact Inventory: 4 files, 11/11/11 rows, finite/unique | satisfied |
| `FESA-REQ-LS3DEB-042` | Exact component/source identity and endpoint-consistency/no-average policy pass. | `T22-RECOVERY-006`, `T24-REF-004`, `T24-B33-001` | `RV26`: displacement 66, reaction 66, section 44; endpoint consistency true | satisfied |
| `FESA-REQ-LS3DEB-043` | Build precedes reference, reference precedes physics, and physics covers required checks. | `BT25`, `RV26`, `PE27`; phase Steps 25-27 | `PE27`: force/moment equilibrium, reaction, displacement, symmetry, section/end force, residual and coverage pass | satisfied |
| `FESA-REQ-LS3DEB-044` | No reference solver/artifact mutation occurs and release claims no excluded support. | `T12-MAP-004`, `T12-MAP-005`; `BT25`/`RV26`/`PE27` no-change assertions; Step 28 Git audit | exact legacy diff/status clean; this report's Release Scope and Known Limitations | satisfied |

Audit result: all 44 expected `must` requirements have an acceptance criterion, exact executable
or gate evidence, reference/analytical evidence or an explicit applicable N/A, and a final
disposition. No must requirement is deferred or blocked.

## Validation Evidence

| command or report | expected | observed | result |
| --- | --- | --- | --- |
| Step 25 fresh MSVC x64 Debug configure/build | exit 0; `/W4 /WX`; no warnings | exit 0; warning scan 0 | pass |
| Step 25 CTest discovery/full | nonzero discovery; zero failures | 83 discovered; feature 83/83; full 83/83 | pass |
| exact Build/Test gate string | `status: pass-for-reference-verification` | present | pass |
| exact Reference Verification gate string | `status: pass-for-physics-evaluation` | present; comparison test twice 1/1 | pass |
| exact Physics Evaluation gate string | `status: pass-for-release-agent` | present; targeted physics selection 17/17 | pass |
| reference comparison | exact rows/metrics; approved tolerance | 176/176 rows, 16/16 metrics, `passed=true`; largest normalized error `0.026602795021994977 < 1` | pass |
| physics sanity | equilibrium/sign/symmetry/section/residual/coverage pass | force `1.1921e-13`, moment `2.7418e-13`, free residual `9.3563e-13`; all checks pass | pass |
| phase prerequisites | Steps 0-27 completed | all 28 prerequisite entries completed | pass |

## Release Checklist

- [x] Approved design, requirements, research, formulation, numerical, I/O, and reference-model evidence is present.
- [x] TASK-07 through TASK-24 implementation evidence is complete and independently audited.
- [x] Exact three-gate status strings are present and passing.
- [x] All 44 `must` requirements are traced to acceptance, exact evidence, reference/analytical coverage, and disposition.
- [x] Reference bundle identity and read-only status are preserved.
- [x] Known limitations, accepted Minors, evidence limitations, and explicit N/A items are documented.
- [x] No Critical, unresolved Important, defect, missing artifact, failed command, or user decision blocks internal readiness.

## Known Limitations

| limitation | category | user impact | disposition |
| --- | --- | --- | --- |
| Abaqus `TYPE=B31` / Timoshenko | element/input | rejected as `unsupported-element-formulation`; no shear-deformable beam behavior | documented, deferred feature |
| multiple analysis steps | analysis/input | a second `*STEP` is rejected; no step-to-step propagation | documented, deferred feature |
| instance transforms and nested/dependent assembly | model/input | translation/rotation and nested semantics are rejected | documented, deferred feature |
| `I12!=0` and section extensions | section/physics | coupled inertia, taper, offsets, releases, curved geometry, and warping are unsupported | documented, deferred feature |
| Abaqus `*DLOAD` | load/input | parser/CLI reject it; only the formulation-level constant local line-load kernel exists | documented, deferred feature |
| nonlinear/dynamic/contact/thermal | analysis/physics | no geometric/material nonlinearity, dynamics, contact, or thermal response | documented, deferred feature |
| shear and warping stress | output/physics | no transverse/torsional shear-stress or warping-stress recovery; no nodal averaging | documented, deferred feature |
| beam stress reference | verification | axial `S11` is mandatory and analytically/schema tested, but Abaqus stress reference is N/A | accepted contract N/A |
| approved four-file legacy exception | artifacts | spaces and legacy names remain; `metadata.json`, `README.md`, and stress CSV are N/A only for this bundle | read-only accepted exception; not precedent for new bundles |
| reference coverage | verification | single identity-axis local-z B33 cantilever does not itself cover axial/torsion/local-y/rotated/prescribed/line-load/nonzero-fiber stress | accepted; complementary analytical/unit portfolio passes |
| Euler-Bernoulli applicability | modeling | deep/short beams may be too stiff; no automatic slenderness threshold is approved | documented modeling limit |
| energy evidence | output | no HDF5 energy dataset; Step 27 derives positive `0.5*F^T*d` and uses rank/energy tests | accepted evidence limit |
| comparator file-type depth (Minor) | test evidence | test-only comparator pins float64 types but relies on writer self-check/full schema tests for exact uint64/compound/string file types | accepted defense-in-depth coverage limit |
| multi-source diagnostic order (Minor) | portability/future scope | sorter is sufficient for V0 single-input CLI but is not the future multi-source declaration/internal-ID ordering contract | accepted V0 limit |
| HDF5 `libmmd.dll` staging guard (Minor) | environment portability | unconditional guard is correct for approved shared-HDF5 environment; alternate HDF5 targets may need adjustment | accepted external portability limit |
| stale implementation aggregate header | documentation | top-level `in-progress` can confuse readers despite completed evidence | documented nonblocking stale header; upstream unchanged |

## Release Notes Draft

### Feature Summary

- Adds the internally release-ready FESA V0 end-to-end single-step linear-static 3D
  Euler-Bernoulli beam pipeline for Abaqus `TYPE=B33` input.
- Supports stable identity instances, deterministic DOF/sparse assembly, separate PARDISO
  factorization/substitution, nonzero prescribed displacement, residual reactions, and atomic
  HDF5 `results.h5` output.
- Writes mandatory displacement, reaction, equilibrium end action, endpoint section resultant,
  generalized strain/resultant, and axial `S11` regardless of Abaqus output requests.

### Verification Scope

- Fresh Visual Studio 18 2026/MSVC x64 Debug build passed under `/W4 /WX` with zero warnings and
  all 83 discovered tests passing.
- The approved read-only `cantilever-beam-b33` bundle passed all 176 displacement/reaction/section
  rows and all 16 metric groups under `absolute_floor + 1e-6 * reference_scale`.
- Physics evaluation passed force/moment equilibrium, reactions, displacement/rotation signs,
  zero symmetry, end/section balance, local/global mapping, residual, `S11`, energy/modes, and
  complementary analytical coverage.

### Main Limitations

- No B31, multiple steps, transforms/nested assembly, `I12!=0`, `*DLOAD`, nonlinear, dynamic,
  contact, thermal, shear-stress, or warping-stress support.
- Abaqus beam stress reference comparison is N/A; nonzero `S11` evidence is analytical/unit-based.
- The legacy space-containing four-file reference bundle is a read-only exception. New bundles
  must use canonical names and metadata.
- The single Abaqus cantilever is supplemented by analytical/unit models and does not establish
  full Abaqus B33 compatibility or experimental validation.
- Accepted Minor test-depth and alternate-environment portability limits remain as documented in
  Known Limitations.

### Artifacts

- Authoritative solver output for a run: HDF5 `results.h5`.
- Approved reference baseline: `reference/cantilever beam/` exact four-file legacy bundle.
- Gate evidence: the Build/Test, Reference Verification, and Physics Evaluation reports listed in
  Metadata; deterministic build-local `comparison.json` is review evidence, not solver output.

## Release Verdict

- verdict: `ready-for-release`
- status: `ready-for-release`
- reason: all required upstream gates are present and passing, Steps 0-27 are completed, all 44
  must requirements have complete acceptance/test/reference/disposition traceability, reference
  identity is unchanged, known limitations and accepted risks are documented, and no unresolved
  blocker exists.
- authority_boundary: internal feature readiness only; no publish, deploy, package, tag, push,
  commit, external release, or reference-artifact change is authorized.

## Handoff Recommendation

| target_agent | reason | required input |
| --- | --- | --- |
| Coordinator Agent | Close the internal feature workflow with `ready-for-release`. | This report, exact three-gate reports, phase index Step 28 completion, and the documented authority boundary. |
| Correction Agent | N/A; no implementation-owned blocker exists. | N/A |
| Reference Verification Agent | N/A; required comparison passed. | N/A |
| Physics Evaluation Agent | N/A; required physics review passed. | N/A |

No release engineering, packaging, publication, tag, push, or external coordination was performed.

## No-Change Assertion

- source_files_modified: `false`
- test_files_modified: `false`
- cmake_files_modified: `false`
- requirements_or_upstream_contracts_modified: `false`
- implementation_report_modified: `false`
- build_reference_or_physics_reports_modified: `false`
- reference_artifacts_modified: `false`
- tolerance_policies_modified: `false`
- Abaqus_or_other_reference_solver_executed: `false`
- publish_deploy_package_tag_push_commit_performed: `false`
- owned_release_report_created: `true`
- phase_index_step28_modified: `true`
- notes: Step 28 changes are limited to this report and the Step 28 object in the phase index;
  reference evidence and all upstream files were inspected read-only.

## Open Issues

- Blocking issues: none.
- Nonblocking documentation issue: the implementation report aggregate `status: in-progress` is
  stale; completed Step blocks, phase index, and Step 25 fresh audit are authoritative for release
  closure. It remains unchanged to preserve upstream audit independence.
- Nonblocking evidence-text issues: Step 26 documents the stale sample `status` probe versus
  authoritative `passed=true`, and the Step 25 input-hash prose typo. Later exact hashes and Git
  audits resolve identity without changing artifacts.
- Nonblocking accepted Minors: comparator file-type defense-in-depth coverage, future multi-source
  diagnostic ordering, and alternate-HDF5 `libmmd.dll` staging portability remain as documented.
- Deferred behavior is limited to the Known Limitations and is not claimed as supported.